noun. a surveying instrument for measuring horizontal and vertical angles, consisting of a small telescope mounted on a tripod.
1. Noun, singular or mass If you were to draw an arc to the right from the theodolite to the object being surveyed the top number would give you the angle measure of that arc. 2. Adjective Repeating theodolites are considered more accurate than other theodolite types because errors are reduced by comparing values of multiple readings instead of a single reading.